Monitoring radon emission anomalies at Stromboli Island as a tracer of eruptive events and “near field” earthquakes

G Gervino,L Periale,Corrado Cigolini ,Andrea Lavagno ,Diego Coppola ,Marco Laiolo

doi:10.1051/epjconf/20122405002

G Gervino, L Periale + Show 4 more

Open Access

https://doi.org/10.1051/epjconf/20122405002

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Abstract

Radon emission from soil at Stromboli Island has been monitored since 2002 utilizing a network of 25 stations and exposing two kinds of detectors: E-PERM and calibrated track-etches (LR115). We present and discuss the data from 2002 to 2007, thus including the last two major eruptive cycles. Earthquake-volcano interactions were detected providing evidence that radon emissions are somehow related to the occurrence of regional earthquakes. Single deep earthquakes related to active subduction, such as Salina event (ML =5 .1) of May 5, 2004, may be capable of increasing the ascent of geothermal fluids due to the passage of seismic waves. In addition, we observed major eruptions at Stromboli were preceded by anomalies that occurred at three summit stations that reached values above 20000 Bq m −3 : this is considered an anomalous value and could be regarded, under particular environmental conditions, as a potential precursory signal of a change in volcanic activity.

Highlights

Radon survey at Stromboli Volcano was systematically performed by a network of 21 stations from May 2002 to June 2007
Radon emission from soil at Stromboli Island has been monitored since 2002 utilizing a network of 25 stations and exposing two kinds of detectors: E-PERM and calibrated track-etches (LR115)
We present and discuss the data from 2002 to 2007, including the last two major eruptive cycles

Summary

Introduction

Radon survey at Stromboli Volcano was systematically performed by a network of 21 stations from May 2002 to June 2007. The effects of daily temperature variations and soil humidity on radon emissions are minimized, at least for the LR115 detectors since they give an integrated measurement over a rather long exposure time By using the above alpha particles detection technique, radon can be monitored even when it is in extremely low concentrations It may be used as a tracer to investigate the movement of geothermal fluids as well. Volcanic activity at Stromboli Volcano is characterized by a continuous and mild explosive activity, with eruptions of ashes, lapilli, scoriae and bombs that are ejected at the active summit vents. This typical and persistent activity may be periodically replaced by lava effusions, major explosions and paroxysms

Radon measurements

Findings

Conclusions